Abstract: A transmitter portion 14 includes a control circuit 32, a driver circuit 33, and a wave detector circuit 35. The control circuit 32 generates control signals Vp, Vn based on a pulsed transmission signal So. The driver circuit 33, which is supplied with a battery voltage Vb, generates an output signal Sa to be sent to an antenna 13 based on the control signals Vp, Vn. The wave detector circuit 35 outputs a detection signal Sk having a voltage proportional to the level of the output signal Sa (transmission power level). The control circuit 32 changes the pulse widths of the control signals Vp, Vn based on the voltage level of the detection signal Sk. As a result, electric power consumption is reduced and enlargement of an apparatus is suppressed while maintaining the transmission power level constant.

Abstract: A multi-frequency antenna includes a ground conductor portion, a first radiation conductor portion serving as a first radiation element facing the ground conductor portion keeping a predetermined distance therefrom, a short circuit portion connecting an end portion of the first radiation conductor portion and the ground conductor portion, and a planar shaped second radiation conductor portion serving as a second radiation element and having a frequency characteristic different from the first radiation element, the second radiation conductor portion having a first end connected to the first radiation conductor portion and a second end connected to a feeding device.

Abstract: A transmission/reception antenna (21) comprises a core (31) and a coil (32) wound around the core (31). One of a plurality of core sheets (31a) constituting the core (31) is utilized as a sensor electrode (23). Conductors (33, 34) extending from the two ends of the coil (32) are connected to a transmission/reception drive circuit (22). The conductor (35) extending from a capacitance detector (24) is connected to one of the conductors (33, 34) extending between the coil (32) and the transmission/reception drive circuit (22). Consequently, the capacitance detector (24) is alternately connected to the sensor electrode (23) through a parasitic capacitance C1 generated between the coil (32) and the sensor electrode (23) (core sheet (31a)).

Abstract: A transmission/reception antenna (21) comprises a core (31) and a coil (32) wound around the core (31). One of a plurality of core sheets (31a) constituting the core (31) is utilized as a sensor electrode (23). Conductors (33, 34) extending from the two ends of the coil (32) are connected to a transmission/reception drive circuit (22). The conductor (35) extending from a capacitance detector (24) is connected to one of the conductors (33, 34) extending between the coil (32) and the transmission/reception drive circuit (22). Consequently, the capacitance detector (24) is alternately connected to the sensor electrode (23) through a parasitic capacitance C1 generated between the coil (32) and the sensor electrode (23) (core sheet (31a)).

Abstract: A transmitter portion 14 includes a control circuit 32, a driver circuit 33, and a wave detector circuit 35. The control circuit 32 generates control signals Vp, Vn based on a pulsed transmission signal So. The driver circuit 33, which is supplied with a battery voltage Vb, generates an output signal Sa to be sent to an antenna 13 based on the control signals Vp, Vn. The wave detector circuit 35 outputs a detection signal Sk having a voltage proportional to the level of the output signal Sa (transmission power level). The control circuit 32 changes the pulse widths of the control signals Vp, Vn based on the voltage level of the detection signal Sk. As a result, electric power consumption is reduced and enlargement of an apparatus is suppressed while maintaining the transmission power level constant.

Abstract: A capacitance change detection device includes a sensor electrode, and an electrode capacitance measurement device for measuring capacitance of the sensor electrode on the basis of a correlation value based on a reference capacitance at every first predetermined time. A detection signal is generated when a current measurement value of capacitance is changed by equal to or greater predetermined threshold value than a measurement value obtained a second predetermined time before the current measurement value is measured. The capacitance change detection device further includes a sensitivity compensation capacitance for generating capacitance variations equivalent to specific variations of capacitance of the sensor electrode, and being switched between a connected state and a disconnected state. The threshold value is determined as a difference between measurement values of capacitance of the sensor electrode measured at the connected state and at the disconnected state.

Abstract: A capacitance detection apparatus includes a first open/close switch provided between both ends of a standard capacitor, one end of the standard capacitor being connected to a first voltage source, a second open/close switch provided between one end of a first capacitor to be measured and the other end of the standard capacitor, the other end of the first capacitor to be measured being connected to a second voltage source or free space, a third open/close switch provided between both ends of the first capacitor to be measured, a voltage measurement means for measuring voltage of the other end of the standard capacitor, a switch control means for performing a first switching control performing a first switching operation to open the first open/close switch after closing thereof, performing a second switching operation to open the second open/close switch after closing thereof, and a third switching operation to close the third open/close switch after closing thereof, wherein the second and third switching oper

Abstract: A capacitance change detection device includes a sensor electrode, and an electrode capacitance measurement device for measuring capacitance of the sensor electrode on the basis of a correlation value based on a reference capacitance at every first predetermined time. A detection signal is generated when a current measurement value of capacitance is changed by equal to or greater predetermined threshold value than a measurement value obtained a second predetermined time before the current measurement value is measured. The capacitance change detection device further includes a sensitivity compensation capacitance for generating capacitance variations equivalent to specific variations of capacitance of the sensor electrode, and being switched between a connected state and a disconnected state. The threshold value is determined as a difference between measurement values of capacitance of the sensor electrode measured at the connected state and at the disconnected state.

Abstract: A capacitance detection apparatus includes a first open/close switch provided between both ends of a standard capacitor, one end of the standard capacitor being connected to a first voltage source, a second open/close switch provided between one end of a first capacitor to be measured and the other end of the standard capacitor, the other end of the first capacitor to be measured being connected to a second voltage source or free space, a third open/close switch provided between both ends of the first capacitor to be measured, a voltage measurement means for measuring voltage of the other end of the standard capacitor, a switch control means for performing a first switching control performing a first switching operation to open the first open/close switch after closing thereof, performing a second switching operation to open the second open/close switch after closing thereof, and a third switching operation to close the third open/close switch after closing thereof, wherein the second and third switching oper

Abstract: To provide a loop antenna device which inhibits the unnecessary radiation of the electric wave and which can increase the sending speed of data placed on the electric wave. The first loop antenna 14 includes the coil L11 and the resonant capacitor C1 and constitutes a series resonant circuit in which the oscillator is connected in series to the coil L11 and the resonant capacitor C1. The second loop antenna 15 includes the coil L2 and the resonant capacitor C2 which are connected each other in parallel and constitutes a parallel resonant circuit. The second loop antenna 15 is magnetically connected to the first loop antenna 14 via the link coil L12. The switching elements 14, 15 are connected to the first and second loop antennas 14, 15 and the damping is performed to the resonant circuits of the antennas 14, 15 when the switching elements 18, 19 become OFF condition by the control signal from the controller 9.

Abstract: An Amplitude Shift Keying (ASK) modulating circuit includes an oscillation circuit generating a pulse oscillation having a given frequency. A frequency divider is provided having a binary counter unit and having at least an input terminal, an output terminal and a reset terminal. The frequency divider is active and inactive when the reset terminal thereof is applied with low and high levels of a transmission signal wave, respectively, and divides the pulse oscillation while the frequency divider is active. The transmission signal wave is modulated together with a carrier frequency which is identical to the divided frequency.

Abstract: [OBJECT]To provide a loop antenna device which inhibits the unnecessary radiation of the electric wave and which can increase the sending speed of data placed on the electric wave.

Abstract: A door approach transmission apparatus comprises an outside door handle 20 having a conductor with a slit 23 disposed in the door handle surface. A slot antenna 21, 23, 24, 25 is disposed at the slit 23, and includes feeding points 24, 25 installed on the conductor. The apparatus also includes a transmitter 26 for applying voltage for radio wave oscillation to the feeding points 24, 25. The above-described door approach transmission and reception apparatus can be used in a door lock control apparatus where a search radio wave is emitted from a vehicle, a portable wireless device 10 receives the search radio wave, and returns an ID signal. An electrically driven door lock apparatus 40 is driven to unlock the door when the returned ID signal coincides with a registered ID signal. The search radio wave is irradiated from the slot antenna. Either of a transmitter 26 and a receiver 33 is selectively connected to the feeding points 24, 25.

Abstract: A remote control apparatus comprises a vehicle-mounted unit including a transmitter (26, 28, 23) for transmitting an ID request, a receiver (32, 33) for receiving a reply ID transmitted in response to the ID request, controller (31) for controlling the operation state of equipment (40, 60) depending on whether the receiver (32, 33) receives the ID, as well as a portable unit (10) for transmitting a reply ID in response to the ID request. When a hand sensor (1) provided in a door handle of a vehicle senses no hand and the receiver (32, 33) receives an ID, the controller (31) decreases the transmission power of the ID request. The hand sensor (1) comprises a slot antenna having an outside door handle, the surface of which is formed of a conductive material, a slit formed in the conductive material, and feeding points. The antenna is used for transmission of the ID request.

Abstract: A loop antenna has a first antenna generating a first magnetic field and a second antenna generating a second magnetic field such that the first magnetic field and the second magnetic field each have a different axis. A serial resonant circuit and a parallel resonant circuit are provided for the first antenna and the second antenna, respectively. The serial resonant circuit has a ferrite member, a first coil wound around the ferrite member, a resonant capacitor, and a power source connected thereto in series. The in-series connection of the resonant capacitor and the power source are connected across the first coil. The parallel resonant circuit has a link coil wound around the ferrite member, a second coil connected to the link coil in series and wound around a member outside the ferrite member, and a resonant capacitor connected in parallel to the series connection of the second coil and the link coil.

Abstract: A vehicle door lock control apparatus includes a remote control unit that provides instructions to effect a lock condition or an unlock condition of a door look mechanism, a door handle switch which detects the operating condition of a door handle, a door lock control unit that effects the lock condition or the unlock condition of the door lock mechanism in response to signals produced by the door handle switch or the remote control unit, and a contact electrode connected to the door lock control unit for detecting operation of the door handle through contact by a user. The remote control unit has an electrode that establishes a capacitance combination between the remote control unit and the door lock control unit.

Abstract: An information communication system including an order station for transmitting a command signal to a mobile station, the mobile station including a memory for storing information representing that it has received the transmitted command signal from the order station, but has not responded to the command signal.

Abstract: An image processing device for converting a scanned image into a monochrome image includes a scanner for providing an image signal which is applied to a sampling and holding circuit. The output of the scanning and holding circuit is supplied to a peak hold circuit and to a comparator. The output of the peak hold circuit is also applied to the comparator and the output of the comparator is supplied to a D-type flip flop circuit, the output of which is fed back to the input to the comparator from the scanning and holding circuit. The D-type flip flop generates an alteration of black and white level signals when the output from the sampling and holding circuit is close to the threshold level whereby a printer will print alterations of black and white dots.

Abstract: An information communicating system and method comprising an order station and a plurality of mobile stations. When the order station cannot communicate with a mobile station, the order station selects one mobile station which is nearest to the uncommunicable mobile station and orders the selected mobile station to communicate with the uncommunicated mobile station. Communicable mobile station send information to the order station. The selected mobile station communicates with the uncommunicable mobile station appointed by the order station according to an order from the order station, and transmits the position information of uncommunicable mobile station to the order station. The order station displays the position of the mobile station to control movement of the mobile station.

Abstract: A power supply circuit for an automobile including an electric automotive appliance having a memory, a main battery, a backup battery, an ignition key switch, a battery switching circuit for connecting one of the main and backup batteries to the electric automotive appliance, a power detector for detecting a charged power in the backup battery, a limiting circuit for limiting the operation of the electric automobile appliance to only a power backup of the memory, and a control circuit for activating the limiting circuit when a charged power in the backup battery is detected to be below a predetermined level.